Memory Device Having Resistance Change Material and Operating Method for the Memory Device

1. A memory device, the memory device comprising: a memory cell array including at least a first resistive memory cell and a second resistive memory cell, wherein the first resistive memory cell and the second resistive memory cell each include a resistance change material and each are configured to store different data according to a value of their resistance; a buffer including a first storage region and a second storage region corresponding to the first resistive memory cell and the second resistive memory cell, respectively; and a control circuit configured to receive program data to be programmed to the memory cell array, to compare first data stored in the first storage region and second data stored in the first resistive memory cell, and in response to comparing the first data and the second data to determine one of the first storage region and the second storage region as a selected storage region to which to write the program data.

2. The memory device of claim 1 , wherein the control circuit is configured to write the program data to the first storage region when the first data and the second data are identical, and to write the program data to the second storage region when the first data and the second data are not identical.

3. The memory device of claim 1 , further comprising: an Error Correction Code (ECC) unit configured to perform error detection and correction on the second data stored in the memory cell array, wherein the control circuit is configured to write the program data to the first storage region it is determined that the first data and the second data can be made identical through error detection and correction, and to write the program data to the second storage region when it is determined that the first data and the second data cannot be made identical through error detection and correction.

4. The memory device of claim 1 , wherein the control circuit includes a pointer control circuit which is configured to control a write pointer pointing to a target storage region to which to write the program data, and the pointer control circuit is further configured to control the write pointer to change the target storage region to which to write the program data according to a result of comparing the first data and the second data.

5. The memory device of claim 1 , wherein the memory cell array, the buffer and the control circuit comprise a memory element, the memory device further comprising a memory controller configured to provide the program data and a write command to the memory element.

6. The memory device of claim 1 , wherein the first resistive memory cell and the first storage region are disposed in a first memory element, and the second resistive memory cell and the second storage region are disposed in a second memory element which is different from the first memory element, the memory device further comprising a memory controller which is configured to provide the program data and a write comment to the first memory element and the second memory element.

7. The memory device of claim 1 , wherein the first resistive memory cell and the second resistive memory cell each include a variable resistance element, which comprises a phase-change material, and an access element, which controls a current that flows in the variable resistance element.

8. The memory device of claim 7 , wherein the access element includes an Ovonic Threshold Switch (OTS).

9. A method of operating a memory device, comprising: receiving program data; reading first data stored in a first storage region of a buffer of the memory device, wherein the first storage region is pointed to by a write pointer; reading second data stored in a first resistive memory cell of the memory device, which corresponds to the first storage region and stores different data according to a value of its resistance; comparing the first data and the second data; and writing the program data to the first storage region when comparing the first data and the second data produces a first result, and controlling the write pointer to point to a second storage region of the buffer, which is different from the first storage region, when comparing the first data and the second data produces a second result, which is different from the first result.

10. The method of claim 9 , further comprising: controlling the write pointer to point to the second storage region; comparing third data stored in the second storage region and fourth data stored in a second resistive memory cell, which corresponds to the second storage region; and writing the program data to the second storage region when the result of the comparing the third data and the fourth data, is the first result, and controlling the write pointer to point to a third storage region of the buffer, which is different from the first and second storage regions, when the result of the comparing the third data and the fourth data is the second result.

11. The method of claim 9 , wherein the first storage region and the first resistive memory cell are indicated by a same address.

12. The method of claim 9 , wherein the first result includes a first case in which the first data and the second data are identical, and the second result includes a second case in which the first data and the second data are not identical.

13. The method of claim 9 , wherein the first result includes a case in which the first data and the second data can be made identical through error detection and correction.

14. The method of claim 9 , further comprising: providing a read command; and in response to the read command, outputting read data from one of the buffer and a memory cell array including the first resistive memory cell.

15. The method of claim 14 , wherein providing the read command includes providing a read address, and outputting the read data comprises outputting the read data from the buffer when the read address exists in the buffer, and outputting the read data from the memory cell array when the read address does not exist in the buffer.

16. A method of operating a memory device, comprising: receiving program data; reading first data stored in a first storage region of a buffer of the memory device, wherein the buffer includes the first storage region and a second storage region separate from the first storage region; reading second data stored in a first resistive memory cell of a memory cell array of the memory device, wherein the first resistive memory cell corresponds to the first storage region and stores different data according to a value of its resistance; comparing the first data and the second data; and writing the program data to the first storage region when comparing the first data and the second data produces a first result, and writing the program data to the second storage region when comparing the first data and the second data produces a second result which is different from the first result.

17. The method of claim 16 , wherein the first storage region and the second storage region are disposed in a single memory element of the memory device, and the first resistive memory cell and a second resistive memory cell are also disposed in the single memory element.

18. The method of claim 16 , wherein the first storage region and the first resistive memory cell are disposed in a first memory element of the memory device, and the second storage region and a second resistive memory cell of the memory device are disposed in a second memory element of the memory device, which is different from the first memory element.

19. The method of claim 16 , wherein the first storage region and the first resistive memory cell are indicated by a first same address as each other, and the second storage region and a second resistive memory cell of the memory device are indicated by a second same address as each other.

20. The operating method of claim 16 , wherein the first result includes a first case in which the first data and the second data are identical, and the second result includes a second case in which the first data and the second data are not identical.